﻿// ———————————————————————–
// <copyright file="EventLink.cs" company="The MITRE Corporation">
//    Copyright (c) 2014 The MITRE Corporation. All rights reserved.
//    Licensed under the Apache License, Version 2.0 (the "License");
//    you may not use this file except in compliance with the License.
//    You may obtain a copy of the License at
//    http://www.apache.org/licenses/LICENSE-2.0
//    Unless required by applicable law or agreed to in writing, software
//    distributed under the License is distributed on an "AS IS" BASIS,
//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//    See the License for the specific language governing permissions and
//    limitations under the License.
// </copyright>
// ———————————————————————–
/////////////////////////////////////////////////////////////////////////////////////////////////
// EventLink.cs:
//
// A link to other EM events
//
// Project: IC.NET - CAD Library
// Author:  Jim Cronin - MITRE
/////////////////////////////////////////////////////////////////////////////////////////////////

// Copyright (c) 2014 The MITRE Corporation. All rights reserved.
//
// NOTICE
// This software was produced for the U. S. Government
// under Contract No. FA8721-09-C-0001, and is
// subject to the Rights in Noncommercial Computer Software
// and Noncommercial Computer Software Documentation Clause
// (DFARS) 252.227-7014 (JUN 1995)

using System;
using System.Xml;
using EDXLSharp.NIEMCore;

namespace EDXLSharp.NIEMCADLib
{
  /// <summary>
  /// A link to other EM events
  /// </summary>
  public class EventLink : IComposable
  {
    /// <summary>
    /// The Id of the linked EM Event
    /// </summary>
    public string LinkedEventId { get; set; }

    /// <summary>
    /// The EventTypeDescriptor of the linked Event
    /// </summary>
    public EventTypeDescriptor LinkedEventCategory { get; set; }

    /// <summary>
    /// The type of relationship
    /// </summary>
    public EventLinkRelation LinkRelation { get; set; }

    /// <summary>
    /// Writes this Object to an inline XML Document
    /// </summary>
    /// <param name="xwriter">Valid XMLWriter</param>
    public void WriteXML(XmlWriter xwriter)
    {
      this.Validate();

      xwriter.WriteStartElement(EDXLConstants.EMEventPrefix, "EventLink", EDXLConstants.EMEventNamespace);
      
      //Link Id
      xwriter.WriteStartElement(EDXLConstants.EMEventPrefix, "LinkedEventId", EDXLConstants.EMEventNamespace);
      xwriter.WriteElementString(EDXLConstants.NiemCorePrefix, "IdentificationID", EDXLConstants.NiemCoreNamespace, this.LinkedEventId);
      xwriter.WriteEndElement();

      //Link Category Type
      if (this.LinkedEventCategory != null)
      {
        xwriter.WriteStartElement(EDXLConstants.EMEventPrefix, "LinkedEventCategory", EDXLConstants.EMEventNamespace);
        this.LinkedEventCategory.WriteXML(xwriter);
        xwriter.WriteEndElement();
      }

      //Link LinkRelation Code
      if (this.LinkRelation != null)
      {
        this.LinkRelation.WriteXML(xwriter);
      }
      xwriter.WriteEndElement();
    }

    /// <summary>
    /// Reads this Object's values from an XML NodeList
    /// </summary>
    /// <param name="rootnode">Root XML Node of the Object Element</param>
    public void ReadXML(XmlNode rootnode)
    {
      if (rootnode == null)
      {
        throw new ArgumentNullException("rootnode");
      }

      if (rootnode.LocalName != "EventLink")
      {
        throw new ArgumentException("No EventLink element found!");
      }

      foreach (XmlNode node in rootnode.ChildNodes)
      {
        switch (node.LocalName)
        {
          case "LinkedEventId":
            this.LinkedEventId = node.InnerText;
            break;
          case "LinkedEventCategory":
            this.LinkedEventCategory = new EventTypeDescriptor();
            this.LinkedEventCategory.ReadXML(node.FirstChild);
            break;
          case "EventLinkRelationCode":
            this.LinkRelation = new EventLinkRelation();
            this.LinkRelation.ReadXML(node);
            break;
          default:
            throw new ArgumentException("Unexpected element " + node.LocalName + " in element EventLink");
        }
      }

      this.Validate();
    }

    /// <summary>
    /// Validates this EventLink object
    /// </summary>
    /// <exception cref="EDXLSharp.ValidationException">Thrown if validation fails</exception>
    public void Validate()
    {
      if (string.IsNullOrWhiteSpace(this.LinkedEventId))
      {
        throw new ValidationException("Link Id is missing");
      }

      if (this.LinkedEventCategory == null)
      {
        throw new ValidationException("Link Category is missing");
      }
      this.LinkedEventCategory.Validate();

      if (this.LinkRelation == null)
      {
        throw new ValidationException("Link Relation is missing");
      }
      //this.LinkRelation.Validate();
    }
  }
}
